tle7273 Infineon Technologies Corporation, tle7273 Datasheet - Page 12

• Manufacturer Part Number: tle7273
• Description: Low Drop Voltage Regulator
• Manufacturer: Infineon Technologies Corporation

Circuit Description
Power On Reset and Reset Output
For an output voltage level of
reaches the reset threshold
delay time T
time T
power down (
an external microcontroller.
The TLE 7273 GV50 features an integrated pull-up resistor on the reset output while the
TLE 7273 GV33 and TLE 7273 GV26 have an open drain output requiring an external
pull-up resistor ≥ 5.6 kΩ
resistor of the TLE 7273 GV50 is switched off setting the reset output high ohmic.
Example: Calculation based on the reset sink current and an external pull-up resistor
connection to 5V:
R
Figure 3
1) Referred to pull-up voltage level of 5 V.
Final-/ *Target Data Sheet
extmin
RR
= dU / I
avoids wrong triggering caused by short “glitches” on the
RD
V
V
V
V
V
V
ROH
ROL
RO
V
RO
. The reset function and timing is illustrated in
Reset Function and Timing Diagram
RT
Q
Q
I
<
= (V
V
RT
RTmin
for
T
1)
RD
. At low output voltage levels
t
- V
> T
V
V
ROmin
RT
Q
RR
, the signal at RO remains low for the power-up reset
≥ 1 V, the reset output is held low. When the level of
) a logic low signal is generated at the pin RO to reset
<
) / I
T
RR
RO
= (4.5V - 0.25V) / 1.75mA = 2.42kOhm
12
V
Q
T
Figure
< 1 V the integrated pull-up
RR
V
AET03526.VSD
3. The reset reaction
Q
Rev. 1.0, 2005-11-30
-line. In case of
t
t
t
TLE 7273
V
V
Q
Q